Flexure assembly for a scanner

ABSTRACT

A flexure carriage assembly has a carriage formed of a substantially rigid material. The carriage has four elongate columns arranged spaced apart and parallel to one another. Each of the elongate columns has first and second ends. The flexure carriage has four first cross members disposed between adjacent pairs of elongate columns and arranged to interconnect the first ends. The flexure carriage also includes four second cross members arranged between adjacent pairs of elongate columns and arranged to interconnect the bottom ends. The elongate columns and first and second cross members define a three-dimensional rectangular structure. The flexure carriage also has disposed centrally between the four elongate columns a translating section spaced equidistant between the first and second ends of the columns. A plurality of flexures are disposed between the translating element and elongate columns and between the elongate columns and first and second cross members in order to permit precise movement of the translating section in a plane according to applied forces against edges of the translating section. A pair of piezoelectric assemblies are connected to the translating section. One applies force to the translating section in a first linear path and the other applies force to the translating section in a second linear path perpendicular path.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to a high resolutionmeasuring device, and more particularly to a flexure assembly of a microscanning device.

[0003] 2. Discussion of the Related Art

[0004] Flexure carriages and devices are known in the art and are usedfor high resolution instrumentation and measuring equipment such asscanning probe microscopes and the like. These flexure devices typicallycarry thereon a probe or a sensor, or a specimen to be analyzed. Eitherthe specimen or the probe is moved in very small increments in a planerelative to the other for determining surface or subsurfacecharacteristics of the specimen. These devices are typically designed soas to move highly precisely and accurately in an X-Y plane and yet movevery little in a Z direction perpendicular to the X-Y plane. The sensingprobe typically measures surface defects, variation of the specimen'scomponents, surface contour or other surface or subsurfacecharacteristic. These types of devices may also be designed and utilizedfor other applications as well, such as imaging and measuring propertiesof computer microchips, computer disc surfaces, and other physical orchemical properties. The range of measurement for such devices istypically on the order of one Angstrom (Å) to several hundred microns(μ).

[0005] In order to provide this type of extremely high resolutionmeasurement, these devices require precise and minute micro-positioningcapabilities within an X-Y plane and yet ideally permit no movement in aZ direction perpendicular to the plane. The flexure devices or carriageswhich hold the sensing probe or specimen of such devices are designedand utilized to provide just such movement.

[0006] A known flexure carriage construction uses a piezoelectricactuator which utilizes an applied electric potential to micro-positionportions of the flexure devices. Conventional or known devices typicallycan only provide very flat movement in an X-Y plane over a very smallrelative area. The larger the range of movement, the greater theout-of-plane movement becomes, (i.e., the motion becomes increasinglycurved or less flat). This is because of the construction andarrangement of the piezoelectric element in the devices. Thepiezoelectric elements bend partially out of their longitudinal axis andtherefore apply out of axis forces which induce errors. The out of axisforces and resultant errors increase with increased expansion of thepiezoelectric elements.

[0007] One device, disclosed in U.S. Pat. No. 5,360,974 and assigned toInternational Business Machines Corporation of Armonk, N.Y., provides afairly flat movement in an X-Y direction or plane utilizing a dual framearrangement where each frame is supported in opposite directions byflexible legs. Any Z direction motion perpendicular to the plane of oneframe of the device is cancelled by movement of the other frame tomaintain a very flat movement. However, the disclosed device utilizeslong external piezoelectric elements which are oriented parallel to theplane of movement in order to eliminate or reduce rotation or yawproduced by the device. Such a device is much too large in certainapplications.

[0008] Applications that employ such minute micro-positioning andsensing technology increasingly demand higher resolution measurements.For example, computer technology continues to reduce the size andincrease the package density for the electronic elements in microchipsand circuits. Meanwhile, the volume in which they are being produced andthus the size of the wafers on which they are made is also increasing.It is therefore becoming increasingly necessary to provide flexuredevices which are capable of relatively large ranges of movement in anX-Y plane, which prevent movement in a Z axis perpendicular to theplane, and which are relatively small in size so that they may beutilized in equipment that must be smaller, less expensive and moreaccurate. It should be understood that while measurement on a smallerscale is being discussed, changes to a sample on similar scales, such asnano-lithography and micro-machining, may also need to be performed withthis level of accuracy.

[0009] Thus, the discussion herein is intended to encompass fabricationas well as measurement.

SUMMARY OF THE INVENTION

[0010] The present invention is therefore directed to an improvedflexure carriage and assembly useful in high resolution measurement andfabrication devices and instruments. The flexure carriage of theinvention provides extremely flat and true movement in an X-Y directionor plane and prevents movement in a Z direction perpendicular to the X-Yplane. Additionally, the flexure carriage of the invention is capable ofproducing a relatively large range of motion in both the X and the Ydirection while producing such a flat plane of motion. The flexurecarriage of the invention produces such advantages and yet may beconstructed in a relatively small and very sturdy or stiff package toproduce the very flat plane of motion in the X and Y directions.

[0011] To accomplish these and other objects, features and advantages ofthe invention, a flexure assembly or carriage is disclosed. In oneembodiment the flexure carriage of the invention is formed of asubstantially rigid material and has four elongate columns arrangedspaced apart and parallel to one another. Each of the elongate columnshas a first and a second end. The carriage also has four first crossmembers arranged so that each first cross member extends between andinterconnects two first ends of the elongate columns. The carriage alsohas four second cross members arranged so that each second cross memberextends between and interconnects two second ends of the elongatecolumns. The carriage has a translating section that is disposed withina space between the elongate columns generally equadistant between thefirst and second ends of the elongate columns. The translating sectionis interconnected to the elongate columns. The carriage has a pluralityof flexures wherein one flexure interconnects each first end of eachelongate column to each first cross member. One flexure interconnectseach second end of each elongate column to each second cross member. Atleast one flexure interconnects each elongate column with a translatingsection. The flexures permit the translating section to move accordingto an applied force in a plane which is essentially perpendicular to theorientation of the elongate columns. The symmetry of the flexurecarriage eliminates virtually any movement in a Z directionperpendicular to the X -Y plane.

[0012] In one embodiment, a pair of flexures interconnect each elongatecolumn with the translating section. One flexure of each pair isdisposed adjacent the translating section on each elongate column nearerthe first end. The other flexure of each pair is disposed adjacent thetranslating section on each elongate column nearer the second end.

[0013] In one embodiment, each flexure of the flexure carriage includesa first pair of opposed slots formed transversely and extending towardone another into one of the elongate columns. A first web of thesubstantially rigid material is left remaining between the first pair ofslots. A second pair of opposed slots are spaced from the first pair ofslots in the same elongate column and formed transversely and extendingtoward one another into the elongate column. A second web of thesubstantially rigid material is left between the second pair of slots.The first web and the second web are arranged perpendicular to oneanother and spaced apart along the same elongate column.

[0014] In one embodiment, a flexure carriage as described above, isprovided with a first piezoelectric assembly connected to thetranslating section for moving the translating section along only afirst linear path generally perpendicular to the elongate columns. Asecond piezoelectric assembly is connected to the translating sectionfor moving the translating section along only a second linear pathgenerally perpendicular to the elongate columns and perpendicular to thefirst linear path.

[0015] In one embodiment, a high resolution measurement device isconstructed according to the invention and has a support structurecarrying various elements of the device. The measurement device also hasa meauring instrument which is carried by the translating section of aflexure carriage provided as described above. Each of the piezoelectricassemblies is affixed at one portion to the support structure of themeasurement device and affixed to a portion of the translating sectionof the flexure carriage for providing applied forces to the translatingsection for moving the translating section and the measuring instrumenttherewith.

[0016] These and other objects, features and advantages of the presentinvention will be better understood and appreciated when considered inconjunction with the following detailed description and accompanyingdrawings. It should be understood however that the following descriptionis given by way of illustration and not of limitation though itdescribes several preferred embodiments. Many changes and modificationsmay be made to the disclosed embodiments without departing from thespirit and scope of the present invention and the invention is intendedto include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Several embodiments of the present invention are illustrated inthe accompanying drawings in which like reference numerals representlike parts throughout, and in which:

[0018]FIG. 1 illustrates an elevational perspective view of a flexureassembly constructed in accordance with one embodiment of the presentinvention;

[0019]FIG. 2A illustrates an elevational perspective view of the flexurecarriage assembly of the flexure assembly illustrated in FIG. 1;

[0020]FIG. 2B illustrates an elevational perspective view of the flexurecarriage of the assembly shown in FIG. 2A;

[0021]FIG. 3 illustrates a plan view of one side of the flexure carriagewhich is arbitrarily designated as the side;

[0022]FIG. 4 illustrates a plan view of another side of the flexurecarriage illustrated in FIG. 3 rotated 90 degrees on a vertical axis Zand arbitrarily designated as the back;

[0023]FIG. 5 illustrates an enlarged view of a flexure of the flexurecarriage illustrated in circle V of FIG. 3;

[0024]FIG. 6 illustrates an enlarged view of a flexure of the flexurecarriage illustrated in circle VI of FIG. 4;

[0025]FIG. 7 is a sectional elevation view of a portion of the flexurecarriage, illustrating the flexure carriage in an at-rest position insolid lines and in a deflected position in phantom lines; and

[0026]FIG. 8 is a sectional side elevation view of another portion ofthe flexure carriage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention generally discloses a micro-positioningmotion transducer in the form of a flexure device. The flexure deviceincludes a rigid frame or support structure securely carrying a flexurecarriage assembly. The flexure carriage assembly includes a carriagehaving a plurality of structures which permit high precisiontranslational movement in an X and a Y direction defining asubstantially flat plane of movement. The structure precisely transmitsforces at least partially applied in the X direction that are convertedto translational movement of a translational section only in the Xdirection. The structure also transmits forces at least partiallyapplied in the Y direction into translational movement of thetranslational section only in the Y direction. The structure essentiallyprevents any substantial movement of the translational section of thecarriage in a Z direction perpendicular to the X-Y plane. The flexurecarriage assembly includes a pair of piezoelectric assemblies that drivethe translating section of the flexure carriage. One piezoelectricelement drives the translating element in the X direction and the otherpiezoelectric element assembly drives the translating element in the Ydirection. The piezoelectric assemblies are oriented substantiallyparallel to the Z axis, though they impart precision movement in the X-Yplane perpendicular to the Z axis.

[0028] Referring now to the drawings, FIG. 1 illustrates generally aflexure device 20 having a frame or support structure 22 and a flexurecarriage assembly 24 rigidly affixed to and supported by the frame. Thecarriage assembly 24 includes a carriage 25 and also includes a pair ofpiezoelectric assemblies 26 each having opposed distal end couplers 28fixed to the frame 22. The piezoelectric assemblies 26 have a centralcoupler 30 fixed to a translating section 29 of the flexure carriage 25.In general, the frame or support structure 22 can be a separate frameelement as is illustrated in FIG. 1 that is further attached to asuitable instrument or device. Alternatively, the frame 22 can be anintegral portion of the instrument or device (not shown). Thepiezoelectric elements 26 are energized from a source of electric energy(also not shown) and, in accordance with known principles of suchelements, the piezoelectric assemblies 26 move according to the appliedenergy. Since the elements have a central coupler 30 coupled to thetranslating section 29 of the flexure carriage 25, the translatingsection as described in detail below, moves in accordance with themotion of the piezoelectric assemblies 26. As described and shownherein, the movement of the piezoelectric assemblies 26 and thetranslating section 29 of the flexure carriage 25 is highly precise andhas a relatively large range of motion. However, as discussed above, thetypical and desirable range of motion for such a device is small inreality, for example, on the order of one Å to about a few hundred μ.

[0029]FIG. 2A illustrates the flexure carriage assembly 24 inperspective view. FIG. 2B illustrates the carriage 25 in perspectiveview. FIGS. 3 and 4 illustrate two sides in plan view of the carriage 25which have been arbitrarily selected for illustration. The carriage neednot have a front, back and designated sides. However, for illustrativepurposes, FIG. 3 illustrates a view arbitrarily shown as a back surfaceof the carriage 25, and FIG. 4 illustrates a side surface of thecarriage which can be either side of the carriage when the carriage isrotated 90 degrees about a vertical axis relative to the views in FIGS.3 and 4.

[0030] Turning again to FIGS. 2-4, the flexure carriage 25 of thecarriage assembly 24 is in the form of a rectangular three-dimensionalstructure. The carriage 25 is preferably made from a substantially rigidmaterial such as stainless steel or the like wherein the material is nottoo brittle, soft or flexible so that it may perform the intendedfunctions of the invention. The carriage 25 is comprised of asubstantially symmetrical structure and is described herein including atop and bottom end as well as front, rear and side surfaces. However,these designations are arbitrarily selected and utilized only forsimplicity of description. It will be obvious to one of ordinary skillin the art that the carriage as well as the flexure device 20 can beoriented in any manner and manipulated to any orientation withoutdeparting from the scope of the invention.

[0031] With that in mind, FIG. 2A illustrates the flexure carriageassembly 24 and FIG. 2B illustrates the carriage 25. The carriage 25includes four elongate vertical columns disposed parallel to one anotherand spaced equal distance from one another. Each of the elongate columnsincludes a first end, herein designated as a top end and a second end,herein designated as a bottom end. The four elongate columns areidentified herein for simplicity as 32A, 32B, 32C and 32D. Therespective top ends are identified as 34A, 34B, 34C and 34D. Therespective bottom ends 36 are represented by 36A, 36B, 36C and 36D. Eachof the elongate columns is essentially the same length and oriented sothat each of the top ends terminate in the same plane relative to oneanother and each of the bottom ends terminate in the same plane relativeto one another.

[0032] Each of the top ends of the carriage 25 are interconnected toadjacent top ends of corresponding elongate columns by first crossmembers 38A-D. For example, the cross member 38A extends between the topends 34A and 34B of the adjacent elongate columns 32A and 32B.Similarly, the cross member 38B extends between the top ends 34B and34C, the cross member 38C extends between the top ends 34C and 34D, andthe cross member 38D extends between the top ends 34D and 34A. The firstcross members 38A-D combine to define an arbitrary top 39 of thecarriage 25.

[0033] Similarly, four second cross members 40A-D extend between thebottom ends 36A-D of the elongate columns 32A-D in an identical manner.The four second cross members 40A-D combine to define an arbitrarybottom 41 of the carriage 25. Each of the cross members 38A-D and 40A-Dare arranged at right angles relative to one another when viewed fromeither the top 39 or the bottom 41 of the carriage 25. Thus, thecombination of the cross members 38A-D and 40A-D along with the elongatecolumns 32A-D define a right angle three dimensional parallelogram. Inthe present embodiment, all of the cross members are of equal length sothat the top 39 and bottom 41 are square. A symmetrical shape ispreferred for the carriage but the overall cross section need not be asquare shape in order to fall within the scope of the invention.

[0034] The elongate columns 32 A-D and the cross members 38A-D and 40A-Dare each preferably integrally formed with one another and therefore,without more, would form a rigid frame structure. However, the carriage25 of the flexure device 20 must allow for certain flexible movements asdescribed below in detail. The flexible nature of the carriage 25 isprovided by adding a plurality of flexures 50 to the structure of thecarriage 25. The construction of one flexure 50 is now described indetail below. Subsequently, the placement of the flexures 50 on thecarriage 25 is described along with the function and flexible nature ofthe carriage.

[0035] In order to simplify the description of the carriage 25, acoordinate system is arbitrarily chosen and utilized in conjunction withthe discussion herein. Referring to FIG. 2B, an X axis or X coordinateis defined along one axis perpendicular to the four elongate columns32A-D and perpendicular to arbitrary side surfaces 52 and surface 54. AY axis as illustrated in FIG. 2B is perpendicular to the X axis and alsoperpendicular to an opposed front 56 and back 58 of the carriage 25. Thefront and back 56 and 58, respectively, are perpendicular to the sides52 and 54. A Z axis is also illustrated in FIG. 2B disposed parallel toand between to the four elongate columns 32A-D and perpendicular to theX-Y plane. The arbitrary back 58 is illustrated in FIG. 4 and thearbitrary side 52 is illustrated in FIG. 3.

[0036]FIG. 5 illustrates the construction of one flexure 50 taken at thejuncture between the elongate column 32C at its top end 34C and thecross member 38B. FIG. 6 illustrates the same flexure 50 viewed 90degrees relative to the flexure shown in FIG. 5.

[0037] Each flexure 50 includes an interior first material web 60 nearerthe X and Y plane and an exterior second material web 62 nearer eitherthe top 39 or bottom 41 of the carriage and essentially perpendicularrelative to the first material web 60. Each material web is formed bycreating a pair of opposed slots 64 perpendicularly or transversely intoopposed surfaces of the appropriate elongate column 32. Thus, eachmaterial web 60 and 62 is a thin web or membrane of material between theslots 64 and extends the entire width of the appropriate elongate column32 when viewed into one of the slots 64. Therefore, the view of theflexure 50 in FIG. 5 shows the interior material web 60 on an end viewso that the thin-walled construction is visible. The exterior materialweb 62 is illustrated lengthwise. The same flexure 50 is illustrated inFIG. 6 where the interior material web 60 is lengthwise and the exteriormaterial web 62 is in an end view.

[0038] Each flexure 50 permits linear movement in the X direction andthe Y direction but not in the Z direction. The web 60 will permitslight lateral movement of the elongate column 32C relative to the crossmember 38B when a force is applied in the X direction. The web 62,because it is oriented lengthwise in the X direction and rigidlyconnected to both the cross member 38B and the elongate column 32C,prevents movement in the X direction. However, when viewed at a 90degree angle as shown in FIG. 6, the web 62 permits movement in the Ydirection upon an applied Y direction force.

[0039] Each flexure 50 therefore permits movement in the X direction andthe Y direction upon an applied force, respectively, in the X or the Ydirection. Each flexure 50 also prevents any movement in the Z directionbased on the rigid connections between each structural element connectedto each flexure 50. The construction of each flexure 50 also enhancesdirect movement only in the direction of the applied force in that oneweb is oriented to permit movement only in one linear direction whereinthe other web is oriented to permit movement in only one lineardirection perpendicular to the linear direction of movement for theother web. Each web is also constructed to prevent any movement at thatweb other than in its intended direction of movement. Therefore, eachflexure 50 provides a precise X or Y flexure according to the appliedforce and prevents any other movement and particularly prevents movementin the Z direction.

[0040] As best illustrated in FIG. 2A, a flexure 50 is disposed at eachtop end 34A-D and each bottom end 36A-D between the respective elongatecolumns 32A-D and cross members 38A-D and 40A-D. Each flexure 50disposed at the top ends 34 of the elongate columns 32 is oriented sothat all interior webs 60 are oriented in the same direction relative toone another and all exterior webs 62 are oriented in the directionrelative to one another. Each of the flexures 50 disposed at the bottomends 36 of the elongate columns 32 is also oriented identically relativeto one another. Each flexure 50 disposed at opposite ends of each of theelongate columns 32A-D are preferably oriented as mirror images of oneanother to provide symmetry in the construction of the carriage 25. Forexample, the flexures 50 on ends 34A and 36A of the elongate column 32Aeach have the exterior material webs 62 oriented parallel relative toone another and have the interior material webs 60 oriented parallelrelative to one another.

[0041] Each of the elongate columns 32A-D also has at least one, andpreferably, a pair of flexures 50 disposed near the center defined bythe X axis and Y axis noted in FIG. 2A with one flexure 50 beingdisposed on each side of the mid- line or X-Y plane. Again, each ofthese interior flexures 50 are disposed so that they are mirror imagesrelative to one another. Therefore, the interior material webs 60 areoriented parallel relative to one another and the exterior material webs62 are also oriented parallel relative to one another. Additionally,each of the flexures disposed near the mid-line 50 is orientedidentically on each of the elongate columns 32 A-D to provide uniformflexure.

[0042] The translating section 29 is connected to each of the mid-lineflexures 50 of the carriage. The translating section 29 is disposedcorresponding to the X-Y plane of the carriage 25 so that the carriageis essentially symmetrical on either the top portion or the bottomportion of the carriage 25 relative to the translating section 29. Aforce F applied to a back surface 68 of the translating member in the Xdirection will cause all of the flexures 50 to flex at the appropriatematerial web to permit movement in the X direction as seen in phantomlines in FIG. 7. Because the carriage 25 is constructed symmetrically,any small movement in a Z direction of any particular flexure 50 on oneside of the X-Y plane is negated by mirror image movement of thecorresponding flexure on the other side of the X-Y plane. This mirrorimage movement also offsets emperical strain on the carriage duringmicroactuator actuation. Thus, the translating section 29 moves in avery flat movement along the X-Y plane at the center axis of thecarriage.

[0043] A force applied to a side surface 70 of the translating section29 in the Y direction causes each flexure 50 to bend slightly about theappropriate material web oriented to permit movement in the Y direction.Again, because of the symmetry of the structure, movement in the Ydirection of the translating section 29 will be a very flat planarmovement along the X-Y plane. Because of the construction of theflexures 50 and the carriage 25, any load applied along the Y axis istransmitted as movement only in the Y direction and yields no movementin the X or the Z direction. Loads applied in both the X direction andthe Y direction simultaneously will move the translating section 29 inboth the X direction and the Y direction but only for a distanceaccording to the force vectors in each direction respectively. An Xdirection force produces no substantial movement in the Y direction, anda Y direction force produces no substantial movement in the X direction.Therefore, extremely accurate results are produced by utilizing thecarriage assembly 24 of the invention.

[0044] As illustrated in FIGS. 3 and 4, the carriage 25 includes aplurality of stiffening beams 80 spanning each adjacent pair of elongatecolumns 32A-D and running essentially parallel to the top and bottomcross members 38A-D and 40A-D. Each stiffening beam 80 is connected toan elongate column 32A-D at its opposite ends 82 and 84 by a materialweb 86. Each material web 86 is formed similar to any one of thematerial webs 60 or 62 described above in that a pair of opposed notchesor slots 88 are cut into the carriage material adjacent to each of theends 82 and 84 to form a thin web of material interconnecting thestiffening beams 80 to the elongate columns 32A-D. Each stiffening beam80 essentially locks the adjacent elongate columns 32A-D laterallyrelative to one another so that if they move in either the X or the Ydirection, they will move in tandem and not move closer to or furtheraway from one another. However, the web 86 at each end of eachstiffening beam permits the stiffening beams to pivot slightly relativeto the respective one of the elongate columns 32 A-D so that thecarriage 25 can perform its intended flexure function by allowing thetranslating section 29 to move in the X-Y plane.

[0045] As illustrated in FIGS. 3 and 4, the front 56, back 58, and sides52 and 54 can include a stiffening beam 80 adjacent to each of theflexures 50 to provide lateral support to the carriage structure. Asillustrated in FIGS. 1 and 2B, one side, such as the front 56, can bedevoid of a stiffening beam to permit access to the interior of thecarriage 25. Access may be necessary in order to activate or install orreplace a sensor probe (not shown) or other apparatus attached to orcarried by the translating section 29 of the flexure device. The numberof stiffening beams 80 as well as the position or location of thestiffening beams can vary considerably without departing from the scopeof the present invention. The addition and strength of the stiffeningbeams is determined by the particular application for which the flexuredevice 20 is intended. Some applications may require a stiffer carriage25 while other applications may require a more flexible structure.

[0046] As illustrated in FIGS. 1 and 2A, the back 58 and one side 52 arecoupled to the piezoelectric assemblies 26.

[0047] In the present embodiment, each piezoelectric assembly 26 has apair of piezoelectric elements 90 extending symmetrically outward from acentral block coupler 30 as illustrated in FIGS. 2A and 8. The coupler30 is rigidly affixed to the back surface 68 of the translating section29 for movement therewith. The coupler 30 includes a pair ofsymmetrically opposed flexures 50 essentially identical in constructionto those described above for the carriage 25. Each of the flexures 50 isattached to one of the piezoelectric elements 90. Each piezoelectricelement 90 is attached at their opposite distal ends to a correspondingend coupler 28, which is rigidly affixed to the frame or supportstructure 22 and retained thereby. Each of the end couplers 28 alsoincludes a flexure 50 for coupling the piezoelectric elements 90 to theend couplers 28.

[0048] Each piezoelectric element 90 is electrically connected to apower supply (not shown) wherein the power supply is utilized toenergize each piezoelectric element and to move each element and hencethe translating section 29. The flexures at each coupler 30 and 28permit the piezoelectric elements 90 to drive the central coupler 30 andhence the translating section 29 as described above in either the Xdirection or the Y direction or both depending on how the piezoelectricassemblies 26 are energized.

[0049] The piezoelectric elements 90 are intended to be identical innature for each piezoelectric assembly 26 so that each piezoelectricelement 90 of a particular assembly produces an equivalent movement.This insures that no out of balance force is applied to the translatingsection 29. Additionally, the movement produced by each piezoelectricassembly 26 is essentially only in the X or the Y direction because ofthe symmetrical construction of the piezoelectric assemblies 26 andbecause each end coupler 28 is rigidly affixed to the frame 22. Anymovement which would otherwise be created in the Z direction at one endof the piezoelectric assembly is cancelled by an opposite and equalreaction at the other end of the assembly 26.

[0050] As illustrated in FIG. 2A, the central couplers 30 of eachpiezoelectric assemby 26 are different in construction. However, theonly difference is in the size of the rigid central portion of thecouplers 30 affixed to the translating section 29. The size of thiscentral portion of the central couplers is merely adapted to coincide orcorrespond to the size and shape of the particular surface 68 or 70 ofthe translating section 29 to which the coupler is attached. The shapeand construction of the end couplers 28 as well as the central couplers30 may vary considerably without departing from the scope and spirit ofthe invention. Additionally, the particular size, type and configurationof the piezoelectric elements may also vary considerably. The inventionis not intended to be limited to any particular piezoelectric elementconstruction.

[0051] To summarize the invention, the structure of the flexure carriage25 transmits an applied force in the X direction into an X directionmovement of the translating section 29 without producing any movement inthe Y direction or the Z direction. Similarly, an applied force in the Ydirection produces movement of the translating section 29 only in the Ydirection without producing any movement in the X direction or the Zdirection. An applied force by both of the piezoelectric assemblies 26produces corresponding movement in both the X and the Y directionwherein the movement in the X direction corresponds only to the appliedX direction force and movement in the Y direction corresponds only tothe applied Y direction force. The construction of the flexure device ofthe invention produces a highly accurate X-Y coordinate movement andproduces such movement in a very flat X-Y plane virtually over arelatively large area while eliminating any significant movement of thetranslating section in the Z direction.

[0052] Many modifications and changes to the invention as described maybe made without departing from the spirit and scope of the invention.For example, the size, shape and construction of each of the elongatecolumns 32A-D, cross members 38A-D and 40A-D, flexures 50, material webs60, 62, and 84, slots 64 and 86, and translating sections 29 may varyconsiderably without departing from the invention. The size, shape andconstruction as well as the materials utilized to produce the flexiblecarriage 25 may be selected and determined according to a particularapplication for which the device 20 is intended. The compact nature ofthe overall carriage assembly 24 including the piezoelectric elements 26permits utilizing the invention in application environments smaller thanpreviously possible. This is accomplished by the novel construction ofthe invention wherein the piezoelectric assemblies 26 are oriented inthe Z direction relative to the X-Y plane of movement of the translatingsection produced by the piezoelectric assemblies.

[0053] Other variations and modifications to the specifically describedembodiments may be made without departing from the spirit and scope ofthe present invention. With that in mind, the invention is intended tobe limited only by the scope of the appended claims.

1. A flexure carriage formed of a substantially rigid material, thecarriage comprising: four elongate columns arranged spaced apart and atleast essentially parallel to one another, each of the elongate columnshaving first and second ends; four first cross members arranged so thateach first cross member extends between and interconnects two first endsof the elongate columns; four second cross members arranged so that eachsecond cross member extends between and interconnects two second ends ofthe elongate columns; a translating section disposed within a spacebetween the elongate columns generally equadistant between the first andsecond ends and interconnected thereto; and a plurality of flexures, atleast one flexure interconnecting each first end of each elongate columnto each first cross member, at least one flexure interconnecting eachsecond end of each elongate column to each second cross member, and atleast one flexure interconnecting each elongate column with thetranslating section.
 2. The flexure carriage according to claim 1 ,further comprising: a pair of flexures interconnecting each elongatecolumn with the translating section, one flexure of each pair disposedadjacent the translating section on each elongate column and nearer thefirst end and one flexure of each pair disposed adjacent the translatingsection on each elongate column and nearer the second end.
 3. Theflexure carriage according to claim 2 , wherein each flexure comprises:a first pair of opposed slots formed transversely and extending towardone another into one of the elongate columns; a first web of thesubstantially rigid material left between the first pair of slots; asecond pair of opposed slots spaced from the first pair of slots in thesame elongate member formed transversely and extending toward oneanother; and a second web of the substantially rigid material leftbetween the second pair of slots wherein the first web and the secondweb are arranged perpendicular to one another and spaced apart along thesame elongate column.
 4. The flexure carriage according to claim 1 ,wherein each flexure comprises: a first pair of opposed slots formedtransversely and extending toward one another into one of the elongatecolumns; a first web of the substantially rigid material left betweenthe first pair of slots; a second pair of opposed slots spaced from thefirst pair of slots in the same elongate member formed transversely andextending toward one another; and a second web of the substantiallyrigid material left between the second pair of slots wherein the firstweb and the second web are arranged perpendicular to one another andspaced apart along the same elongate column.
 5. The flexure carriageaccording to claim 1 , further comprising: a first piezoelectricassembly connected to the translating section for moving the translatingsection along only a first linear path generally perpendicular to theelongate members; and a second piezoelectric assembly connected to thetranslating section for moving the translating section along only asecond linear path generally perpendicular to the elongate columns andto the first linear path.
 6. The flexure carriage according to claim 5 ,wherein each of the piezoelectric assemblies further comprises: acentral coupler formed from a substantially rigid material and having arigid section connected to a portion of the translating section; atleast one flexure connected to the rigid section; and first and secondpiezoelectric elements, the first piezoelectric element extending fromthe at least one flexure toward the first ends of the elongate columnsand the second piezoelectric element extending from the at least oneflexure toward the second ends of the elongate column.
 7. The flexurecarriage according to claim 6 , further comprising: a pair of flexuresconnected to the rigid section, one flexure of the pair interconnectingthe first piezoelectric element and the rigid section and the otherflexure of the pair interconnecting the second piezoelectric element andthe rigid section.
 8. The flexure carriage according to claim 7 ,wherein the at least one flexure further comprises: a first pair ofopposed slots formed into a portion of the central coupler transverselyand extending toward one another; a first web of the substantially rigidmaterial left between the first pair of slots; a second pair of opposedslots spaced from the first pair of slots in the same central couplerformed transversely and extending toward one another; and a second webof the substantially rigid material left between the second pair ofslots wherein the first web and the second web are arrangedperpendicular to one another and spaced apart along the same centralcoupler.
 9. The flexure carriage according to claim 7 , wherein the pairof flexures each further comprise: a first pair of opposed slots formedinto a portion of the central coupler transversely and extending towardone another; a first web of the substantially rigid material leftbetween the first pair of slots; a second pair of opposed slots spacedfrom the first pair of slots in the same central coupler formedtransversely and extending toward one another; and a second web of thesubstantially rigid material left between the second pair of slotswherein the first web and the second web are arranged perpendicular toone another and spaced apart along the same central coupler.
 10. Theflexure carriage according to claim 1 , wherein the four elongatecolumns, the four first cross members, the four second cross members,the translating section, and the plurality of flexures are each formedintegral with one another as a single unitary structure from the samesubstantially rigid material.
 11. The flexure carriage according toclaim 1 , wherein each of the flexures is disposed on the four elongatecolumns.
 12. The flexure carriage according to claim 1 , wherein thetranslating section is connected to at least one flexure on each of theelongate columns.
 13. The flexure carriage according to claim 1 ,further comprising: a flexure disposed on each first end of eachelongate column integrally connected to an end of two adjacent firstcross members.
 14. The flexure carriage according to claim 1 , furthercomprising: a flexure on each second end of each elongate columnconnected to an end of two adjacent second cross members.
 15. Theflexure carriage according to claim 1 , further comprising: a stiffeningbeam disposed between at least one pair of adjacent elongate columns andinterconnected thereto, one stiffening beam near each first end and atleast one near each second end.
 16. The flexure carriage according toclaim 1 , further comprising: a stiffening beam disposed between atleast one pair of adjacent elongate columns between each first end andthe translating section and disposed nearer the translating section, anda stiffening beam disposed between each second end and the translatingsection and disposed nearer the translating section.
 17. The flexurecarriage according to claim 1 , wherein the substantially rigid materialis stainless steel.
 18. A flexure assembly for producingmicro-positioning movement in a plane and preventing movement in adirection perpendicular to the plane, the flexure assembly comprising:four elongate columns arranged spaced apart and parallel to one another,four first cross members arranged extending between and interconnectingto first ends of each of the elongate columns; four second cross membersarranged extending between and interconnecting to second ends of theelongate columns; a translating section disposed equadistant between thefirst and second ends of the elongate columns and interconnectedthereto; a plurality of flexures, one flexure interconnecting each firstend of each elongate column to each first cross member, one flexureinterconnecting each second end of each elongate column to each secondcross member, and at least one flexure interconnecting each elongatecolumn with the translating section; a first piezoelectric assemblywhich is connected to the translating section and which is configured tomove the translating section along only a first linear path generallyperpendicular to the elongate members; and a second piezoelectricassembly which is connected to the translating section and which isconfigured to move the translating section along only a second linearpath generally perpendicular to the elongate members and the firstlinear path.
 19. The flexure assembly according to claim 18 , whereineach of the piezoelectric assemblies further comprises: a centralcoupler formed from a substantially rigid material and having a rigidsection connected to a portion of the translating section; at least oneflexure connected to the rigid section; and first and secondpiezoelectric elements, the first piezoelectric element extending fromthe at least one flexure toward the first ends of the elongate columnsand the second piezoelectric element extending from the at least oneflexure toward the second ends of the elongate column.
 20. The flexurecarriage according to claim 19 , further comprising: a pair of flexuresconnected to the rigid portion, one flexure of the pair interconnectingthe first piezoelectric element and the rigid section and the otherflexure of the pair interconnecting the second piezoelectric element andthe rigid section.
 21. A high resolution measurement device comprising:a measuring instrument; a support structure; and a flexure assemblyhaving a moveable carriage supporting the measuring instrument formovement therewith, wherein the flexure assembly further includes: fourelongate columns arranged spaced apart and parallel to one another, fourfirst cross members arranged extending between and interconnecting tofirst ends of each of the elongate columns; four second cross membersarranged extending between and interconnecting to second ends of theelongate columns; a translating section disposed equadistant between thefirst and second ends of the elongate columns and interconnectedthereto; a plurality of flexures, one flexure interconnecting each firstend of each elongate column to each first cross member, one flexureinterconnecting each second end of each elongate column to each secondcross member, and at least one flexure interconnecting each elongatecolumn with the translating section; a first piezoelectric assemblywhich is connected to the translating section and which is configured tomove the translating section along only a first linear path generallyperpendicular to the elongate members; and a second piezoelectricassembly which is connected to the translating section and which isconfigured to move the translating section along only a second linearpath generally perpendicular to the elongate members and the firstlinear path.